Air cleaner

ABSTRACT

An air cleaner is provided in a cathode system device of a fuel cell system that is mounted in a fuel cell vehicle. The air cleaner comprises a casing having an internal space through which air flows, and an air filter accommodated in the internal space. The air filter has a flat plate shape, and is arranged on an outer side of a fuel cell stack in a horizontal direction, and in a state of being inclined with respect to the horizontal direction.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2019-118183 filed on Jun. 26, 2019, thecontents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an air cleaner provided in a cathodesystem device of a fuel cell system that is mounted in a fuel cellvehicle.

Description of the Related Art

A fuel cell system provided in a fuel cell vehicle takes in air (outsideair) from an outer part of a vehicle by a cathode system device, inorder to supply to a fuel cell stack a cathode gas that is used forgenerating electrical power. Since foreign matter such as dust, dirt,water or the like is included in the air that is taken in, the cathodesystem device includes an air cleaner for removing such foreign matteron an upstream side of a cathode supply pipe.

For example, in Japanese Laid-Open Patent Publication No. 2006-216256,an air cleaner for a fuel cell is disclosed in which a filter isaccommodated inside a casing. In such an air cleaner, the filter isarranged in parallel (horizontal) with respect to the vehicle body, andthe foreign matter is removed by causing the air to flow from a dustside on a lower side of the filter to a clean side on an upper side ofthe filter.

SUMMARY OF THE INVENTION

Incidentally, a filter that is disposed horizontally inside the casingof an air cleaner acts so as to be pushed out with respect to the casingwhen the fuel cell vehicle receives a load from the side (in ahorizontal direction), such as during a collision or the like. For thisreason, the entirety of the air cleaner including the casing may undergomovement and cause damage to peripheral structures (other devices of thevehicle, other devices of the fuel cell system, etc.) of the aircleaner.

The present invention relates to the above-described air cleanertechnology, and has the object of providing an air cleaner which iscapable of easily reducing damage to peripheral structures by easilypromoting collapsing of a casing when a load is received.

In order to achieve the aforementioned object, one aspect of the presentinvention is characterized by an air cleaner provided in a cathodesystem device of a fuel cell system configured to be mounted in a fuelcell vehicle, the air cleaner including a casing having an internalspace through which air flows, and an air filter accommodated in theinternal space, wherein the air filter has a flat plate shape, and isarranged on an outer side of a fuel cell stack in a horizontaldirection, and in a state of being inclined with respect to thehorizontal direction.

The above-described air cleaner is capable of easily promotingcollapsing of the casing when a load is received by the casing. Morespecifically, the air filter, which is arranged in a state of beinginclined with respect to the horizontal direction, positively rotateswithout being pushed out inside the casing when such a load is received.Accordingly, the casing of the air cleaner is smoothly collapsed by theload, movement of the air cleaner itself is suppressed, and damagecaused to peripheral structures around the periphery of the casing canbe significantly reduced.

The above and other objects, features, and advantages of the presentinvention will become more apparent from the following description whentaken in conjunction with the accompanying drawings, in which preferredembodiments of the present invention are shown by way of illustrativeexample.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory diagram of a fuel cell system to which an aircleaner according to an embodiment of the present invention is applied;

FIG. 2A is a front view schematically showing respective devices of acathode system device that is mounted in a vehicle;

FIG. 2B is a side view schematically showing the respective devices ofthe cathode system device that is mounted in the vehicle;

FIG. 3A is a perspective view of an air filter;

FIG. 3B is a partial side cross-sectional view showing a state in whichthe air filter is accommodated in a casing;

FIG. 4A is a partial side cross-sectional view showing operations when aload is received by the air cleaner according to the present embodiment;

FIG. 4B is a partial cross-sectional view showing operations when a loadis received by an air cleaner according to a comparative example;

FIG. 5A is a schematic plan view of a fuel cell system to which an aircleaner according to a modification is applied; and

FIG. 5B is a cross-sectional view taken along line VB-VB of FIG. 5A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be presented anddescribed in detail below with reference to the accompanying drawings.

An air cleaner 70 according to an embodiment of the present invention isapplied to a fuel cell system 10 that is mounted in a fuel cell vehicle11 (fuel cell vehicle: hereinafter, simply referred to as a vehicle 11).As shown in FIG. 1, the fuel cell system 10 includes a fuel cell stack12, an anode system device 14, a cathode system device 16, a coolingdevice 18, and a control device 20 (ECU).

The fuel cell stack 12 includes a plurality of power generation cells22, each of which generates electrical power by an electrochemicalreaction between an anode gas (a fuel gas such as hydrogen or the like)that is supplied from the anode system device 14, and a cathode gas (anoxygen-containing gas such as air or the like) that is supplied from thecathode system device 16. The plurality of power generation cells 22 arestacked along a vehicle widthwise direction of the vehicle 11 withelectrode surfaces thereof being stacked in an upright posture. Itshould be noted that the plurality of power generation cells 22 may alsobe stacked in a longitudinal (front-rear) direction of the vehicle 11 orin the direction of gravity.

Each of the power generation cells 22 includes a membrane electrodeassembly 24 (hereinafter, referred to as an “MEA 24”), and twoseparators 26 that sandwich the MEA 24 therebetween. The MEA 24includes, for example, an electrolyte membrane 28 (for example, a solidpolymer electrolyte membrane (cation exchange membrane)), an anode 30provided on one surface of the electrolyte membrane 28, and a cathode 32provided on another surface of the electrolyte membrane 28. One fromamong the two separators 26 forms an anode flow field 34 through whichthe anode gas is allowed to flow on a surface facing toward the anode30. The other from among the two separators 26 forms a cathode flowfield 36 through which the cathode gas is allowed to flow on a surfacefacing toward the cathode 32. Further, surfaces where the two separators26 face toward each other form a coolant flow field 38 through which acoolant is allowed to flow.

Further, the fuel cell stack 12 is equipped with a plurality of supplypassages (not shown) which allow the anode gas, the cathode gas, and thecoolant to flow along the stacking direction of the power generationcells 22, as well as to flow through the anode flow field 34, thecathode flow field 36, and the coolant flow field 38. The respectivesupply passages communicate with pipes of the anode system device 14,the cathode system device 16, and the cooling device 18 that areconnected to the fuel cell stack 12.

As such pipes, the anode system device 14 includes an anode supply pipe48 for supplying the anode gas to the fuel cell stack 12, and an anodedischarge pipe 50 for discharging an anode off gas used for generatingelectrical power in the fuel cell stack 12. As such pipes, the coolingdevice 18 includes a coolant supply pipe 44 for supplying the coolant tothe fuel cell stack 12, and a coolant discharge pipe 46 for dischargingthe coolant from the fuel cell stack 12.

On the other hand, as such pipes, the cathode system device 16 includesa cathode supply pipe 40 for supplying the cathode gas to the fuel cellstack 12, and a cathode discharge pipe 42 for discharging a cathode offgas used for generating electrical power in the fuel cell stack 12.Further, a bypass pipe 52 is connected between the cathode supply pipe40 and the cathode discharge pipe 42.

The cathode system device 16, which serves as a device for supplying thecathode gas to the fuel cell stack 12, is equipped with the air cleaner70, an air pump 54, an intercooler 56, and a humidifier 58, provided inthis order from an upstream side to a downstream side of the cathodesupply pipe 40.

The air cleaner 70 of the cathode system device 16 removes foreignmatter (dust, dirt, water or the like) contained in the cathode gas(air) when it is drawn in from the outside air. An intake pipe 41 thatconstitutes part of the cathode supply pipe 40 is connected to the aircleaner 70 on a more upstream side than the air cleaner 70. The aircleaner 70 removes foreign matter in the air that has flowed in from aflow passage 41 a inside the intake pipe 41, and clean air flows out tothe air pump 54 on a downstream side of the air cleaner 70. The specificstructure of the air cleaner 70 will be described in detail later.

For the air pump 54, for example, an expander unit 55 including acompressor and an expander is applied thereto. The expander unit 55includes fins (a first fin 55 a 1 and a second fin 55 a 2) at both endsof a rotor 55 a that is accommodated in the interior thereof. Acompressor space on which the first fin 55 a 1 is arranged communicateswith a flow passage 40 a of the cathode supply pipe 40. An expanderspace on which the second fin 55 a 2 is arranged communicates with aflow passage 42 a of the cathode discharge pipe 42.

The rotor 55 a of the expander unit 55 is rotated by a motor mechanism55 b which is controlled by the control device 20. By way of the firstfin 55 a 1, the expander unit 55 supplies the cathode gas to the fuelcell stack 12 through the cathode supply pipe 40, and by way of thesecond fin 55 a 2, recovers energy of the cathode off gas from the fuelcell stack 12 via the cathode discharge pipe 42. Moreover, theconfiguration of the air pump 54 is not particularly limited, and acompressor may be installed in the cathode supply pipe 40, withoutproviding an expander in the cathode discharge pipe 42.

The intercooler 56 cools the cathode gas that flows in from the upstreamside (the side of the expander unit 55) of the cathode supply pipe 40,and causes the cathode gas to flow out on the downstream side (the sideof the humidifier 58). As the intercooler 56, both an air-cooled typeintercooler 56 a (air-cooled type I/C) and a water-cooled typeintercooler 56 b (water-cooled type I/C) are installed in the cathodesupply pipe 40. Moreover, the cathode system device 16 may have aconfiguration in which only one of the air-cooled type intercooler 56 aand the water-cooled type intercooler 56 b is applied thereto.

The humidifier 58 humidifies the cathode gas of the cathode supply pipe40 using the cathode off gas from the cathode discharge pipe 42. Morespecifically, water (generated water) generated due to the electricalpower generation of the fuel cell stack 12 is contained in the cathodeoff gas, and the humidifier 58 causes an appropriate amount of moisturedue to such water to be retained in the cathode gas, and supplies themoisture containing cathode gas to the fuel cell stack 12.

A back pressure valve 60, which adjusts the pressure of the cathode gassupplied to the fuel cell stack 12, is provided in the cathode dischargepipe 42. The back pressure valve 60 is configured, for example, as abutterfly valve, and a degree of opening thereof is controlled on thebasis of the required generated current, or a pressure value or a flowrate value detected by a pressure sensor or a flow rate sensor (neitherof which is shown). Moreover, a gas-liquid separator (not shown) forseparating out the water contained in the cathode off gas may beprovided in the cathode discharge pipe 42 between the humidifier 58 andthe expander unit 55 (the air pump 54).

Further, a bypass valve 62 that opens and closes a flow passage 52 a ofthe bypass pipe 52 is provided in the bypass pipe 52. By beingappropriately opened and closed under the control of the control device20, the bypass valve 62 allows the cathode gas of the cathode supplypipe 40 to flow into the cathode discharge pipe 42, and discharges thecathode gas through the cathode discharge pipe 42.

Next, with reference to FIGS. 2A and 2B, a description will be givenconcerning a state in which the above-described devices of the fuel cellstack 12 and the cathode system device 16 are actually installed in thevehicle 11. A stack case 12 a of the fuel cell stack 12 is formed in arectangular shape extending along the vehicle widthwise direction (thedirection of the arrow A: horizontal direction) as viewed from thefront, and has a predetermined thickness in the longitudinal orfront-rear direction (the direction of the arrow B: horizontaldirection) of the vehicle 11 and the vehicle heightwise direction (thedirection of the arrow C: vertical direction) as viewed from the side.The plurality of power generation cells 22 in the interior of the stackcase 12 a are stacked along the direction of the arrow A in the mannerdescribed above.

At one end (on the side of the arrow A2) of the fuel cell stack 12 (thestack case 12 a) in the direction of the arrow A, an auxiliary equipmentcase 64 is installed, in which several devices of the anode systemdevice 14 and the cathode system device 16 are accommodated. In linewith this fact, the respective devices of the cathode system device 16are also arranged on the side of the arrow A2 of the fuel cell stack 12.

More specifically, the air cleaner 70 is arranged substantially on thefront side of the auxiliary equipment case 64 (the side of the arrowB1), and on the outer side of the auxiliary equipment case 64 (the sideof the arrow A2) in the widthwise direction. Further, the air cleaner 70is arranged at substantially the same height as the fuel cell stack 12,and in particular, on the outer side of the fuel cell stack 12 in thehorizontal direction (the direction parallel to the vehicle body). Theair cleaner 70 is fixed to a vehicle body frame or a mounting frame forthe fuel cell (neither of which are shown).

An opening 41 b of the intake pipe 41 on the upstream side of the aircleaner 70 is disposed at a substantially central portion in the vehiclewidthwise direction and at an appropriate height position. The intakepipe 41 extends initially from the opening 41 b to an outer side (theside of the arrow A2) in the vehicle widthwise direction, and to therear side (the side of the arrow B2), and thereafter, extends obliquelytoward a downward side (the side of the arrow C2) on the front surfaceof the air cleaner 70.

Further, the air pump 54 is arranged downwardly of the air cleaner 70.Stated otherwise, the air pump 54 is located at a position lower thanthe fuel cell stack 12 (the auxiliary equipment case 64) on the side ofthe arrow A2 and on the side of the arrow B1 of the fuel cell stack 12.Between the air cleaner 70 and the air pump 54, a relay pipe 66 aconstituting part of the cathode supply pipe 40 extends in the directionof the arrow C in front of the air cleaner 70 (on the side of the arrowB1).

The air-cooled type intercooler 56 a is arranged at the same heightposition as the air pump 54, and on the outer side of the air pump 54(the side of the arrow A2) in the vehicle widthwise direction.Therefore, a relay pipe 66 b, which constitutes part of the cathodesupply pipe 40 between the air pump 54 and the air-cooled typeintercooler 56 a, extends in the direction of the arrow A.

Further, the water-cooled type intercooler 56 b is positioned atsubstantially the same height as the air-cooled type intercooler 56 a,and is positioned on an inner side (the side of the arrow A1) andrearwardly (on the side of the arrow B2) in the vehicle widthwisedirection with respect to the air-cooled type intercooler 56 a. A relaypipe 66 c, which constitutes part of the cathode supply pipe 40 betweenthe air-cooled type intercooler 56 a and the water-cooled typeintercooler 56 b, extends in the direction of the arrow A and in thedirection of the arrow B through the lower side of the air pump 54.

On the other hand, the humidifier 58 is arranged in the auxiliaryequipment case 64. More specifically, the humidifier 58 is positioned atsubstantially the same height as the fuel cell stack 12 on the side ofthe arrow A2 of the fuel cell stack 12. Between the water-cooled typeintercooler 56 b and the humidifier 58, a relay pipe 66 d thatconstitutes part of the cathode supply pipe 40 extends in the directionof the arrow C. Moreover, another relay pipe (not shown), whichconstitutes part of the cathode supply pipe 40 between the humidifier 58and the fuel cell stack 12, extends to the side of the arrow A1 whileavoiding the respective devices of the auxiliary equipment case 64, andis connected to an end plate (not shown) of the fuel cell stack 12.

Next, a description will be given concerning the configuration of theair cleaner 70 according to the present embodiment. The air cleaner 70comprises a casing 72 having an internal space 72 a through which thecathode gas (air) flows, and an air filter 80 that is accommodated inthe internal space 72 a.

The casing 72 for the air cleaner 70 has a polygonal shape (pentagonalshape) that is extended in the vehicle heightwise direction as viewedfrom the front in FIG. 2A, and has a quadrangular shape as viewed fromthe side in FIG. 2B. The intake pipe 41 is connected to the lower side(the side of the arrow C2) and the front side (the side of the arrow B1)of the casing 72. An air introduction port 73 through which air isintroduced into the internal space 72 a is provided on the casing 72 (alower case 76) that is connected to the intake pipe 41. On the otherhand, the relay pipe 66 a is connected to the upper side (the side ofthe arrow C1) and the front side (the side of the arrow B1) of thecasing 72. An air lead-out port 74 through which air is led out from theinternal space 72 a is provided on the casing 72 (an upper case 78) thatis connected to the relay pipe 66 a.

Further, the casing 72 includes the lower case 76, and the upper case 78joined to an upper side of the lower case 76. More specifically, theinternal space 72 a of the casing 72 is constituted by placing incommunication a lower space 76 a of the lower case 76 and an upper space78 a of the upper case 78. The lower space 76 a and the upper space 78 aare partially partitioned by a non-illustrated partition wall, and apart of the partition wall (a non-formed part of the partition wall)enables communication therebetween. Moreover, the partition wall neednot necessarily be provided between the lower space 76 a and the upperspace 78 a.

The lower case 76 is a portion into which air from the intake pipe 41 isintroduced via the air introduction port 73. The lower case 76 guidesthe air introduced from the intake pipe 41 so as to flow backward (tothe side of the arrow B2), and thereafter, so as to be guided upward (tothe side of the arrow C1). Further, the lower case 76 is capable ofstoring foreign matter (primarily water) contained in the outside air. Awater drainage mechanism (not shown) for draining the stored water ispreferably provided on a bottom wall of the lower case 76.

The upper case 78 is a portion in which the air filter 80 isaccommodated, and according to the present embodiment, is connected toan upper end of the lower case 76 while being inclined toward the innerside (toward the side of the arrow A1) in the vehicle widthwisedirection. More specifically, a pair of side walls 79 a and 79 b in thevehicle widthwise direction (the direction of the arrow A) thatconstitute the upper case 78 are inclined upward and parallel to theside of the arrow A1 (see also FIG. 3B). Further, a ceiling wall 79 e ofthe upper case 78 is connected so as to be perpendicular to the pair ofside walls 79 a and 79 b, and is inclined in a state so that the side ofthe arrow A1 is lower and the side of the arrow A2 is higher. Moreover,side walls 79 c and 79 d in the front-rear direction (the direction ofthe arrow B) that constitute the upper case 78 extend along the vehicleheightwise direction.

The casing 72 (the lower case 76 and the upper case 78) described aboveis configured so that the rigidity thereof is lower (more easilyplastically deformed) than the rigidity of peripheral structures 92 (seeFIG. 3B) disposed around the periphery of the casing 72.

On the other hand, the air filter 80 is accommodated in the upper space78 a of the upper case 78, thereby partitioning the upper space 78 ainto upper and lower parts. Stated otherwise, the upper space 78 a has adust side 78 a 1 on a lower side of the air filter 80, while having aclean side 78 a 2 on an upper side of the air filter 80 (see FIG. 3B).The air lead-out port 74 is in communication with the clean side 78 a 2.

As shown in FIGS. 3A and 3B, the air filter 80 is formed in a flat plateshape. Further, the air filter 80 according to the present embodiment isof a three-layer structure 81 in which three types (a plurality oftypes) of filters (a pre-filter 82, a chemical filter 84, and mainfilters 86) are laminated in the thickness direction. It should be notedthat the structure of the air filter 80 is not particularly limited, andfor example, may be constituted by a single type of filter.

The pre-filter 82 faces toward the dust side 78 a 1, and forms a portionof the air filter 80 through which air initially passes. The pre-filter82 is retained in the upper space 78 a by being joined to one surface ofthe chemical filter 84. As the pre-filter 82, for example, a non-wovenfabric having a predetermined thickness is applied thereto.

The chemical filter 84 constitutes an intermediate layer of the airfilter 80, and air that has passed through the pre-filter 82 passesthrough the chemical filter 84. The chemical filter 84 is constituted,for example, by an aluminum material, and an aluminum honeycomb in whichhoneycomb-shaped holes are arranged in a planar direction is appliedthereto. For example, in the chemical filter 84, an outer peripheralportion thereof is fixed to a frame 88 in which the main filters 86 areheld, and is retained in the upper space 78 a.

The main filters 86 are constituted by pleat-folding sheets throughwhich air is capable of passing. The outer peripheries of the mainfilters 86 are supported by the frame 88. The frame 88 includes an outerperipheral frame 88 a that surrounds the entire circumference of themain filters 86, and an intermediate frame 88 b that extends from thecenter in the front-rear direction (the direction of the arrow B) on aninner side of the outer peripheral frame 88 a. The pair of main filters86 are provided on the inner side of the outer peripheral frame 88 a soas to sandwich the intermediate frame 88 b therebetween. A single mainfilter 86 may be disposed in the outer peripheral frame 88 a, or threeor more of the main filters 86 may be disposed in the outer peripheralframe 88 a. Each of the main filters 86 extends in the direction of thearrow A while being folded back on itself up and down.

A packing 90 (elastic member) is joined to an outer peripheral surfaceof the outer peripheral frame 88 a in a surrounding manner to the outerperipheral frame 88 a. The packing 90 is constituted by an elasticmaterial so as to have an appropriate elastic force, and significantlyprotrudes from the outer peripheral frame 88 a. An outer peripheral sideof the packing 90 is adhered in an airtight manner to the inner surface(the side walls 79 a to 79 d) of the casing 72 (the upper case 78).

In addition, in a horizontal state of the fuel cell vehicle 11, the airfilter 80 according to the present embodiment is fixed to the upper case78 in a state of being inclined through the frame 88 with respect to thehorizontal direction which is perpendicular to the direction of gravity.More specifically, on the outer side of the fuel cell stack 12, the airfilter 80 is inclined with respect to the vehicle widthwise direction(in the direction of the arrow A). Further, as viewed from the front,the air filter 80 is inclined at a predetermined angle with respect tothe direction of extension of the pair of side walls 79 a and 79 b, at aposture in which one side 80 a on the side of the arrow A2 is higher,and another side 80 b on the side of the arrow A1 is lower than theinclination of the ceiling wall 79 e.

The fixing means for fixing the air filter 80 in an inclined posturebetween the casing 72 and the frame 88 is not particularly limited, andfor example, a non-illustrated supporting component may be appropriatelyapplied thereto. The packing 90 provided on the outer periphery of theframe 88 is appropriately deformed into contact with the side walls 79 ato 79 d, and maintains the airtightness of the outer side of the frame88, even in a state in which the frame 88 is inclined and fixed to thecasing 72.

The above-described three-layer structure 81 of the air filter 80connects the mutual filters in a stepped shape. More specifically, thechemical filter 84 is disposed on an inner side of the outer peripheralportion of the main filters 86 including the frame 88, and thepre-filter 82 is disposed on an inner side of the outer peripheralportion of the chemical filter 84.

The air cleaner 70 according to the present embodiment is basicallyconfigured in the manner described above. Next, operations of the aircleaner 70 will be described below.

As shown in FIG. 1, in the fuel cell system 10, under the control of thecontrol device 20, the anode gas is supplied to the fuel cell stack 12from the anode supply pipe 48 of the anode system device 14, and thecathode gas is supplied to the fuel cell stack 12 from the cathodesupply pipe 40 of the cathode system device 16. Further, the controldevice 20 operates the cooling device 18 to circulate the refrigerant,and thereby carries out cooling of the fuel cell stack 12.

Consequently, in the interior of the fuel cell stack 12, the anode gasis supplied to the anodes 30 of the respective power generation cells22, whereas the cathode gas is supplied to the cathodes 32 of therespective power generation cells 22, and the respective powergeneration cells 22 generate electrical power. In addition, at the timethat electrical power is generated, the fuel cell stack 12 dischargesthe anode off gas to the anode discharge pipe 50 of the anode systemdevice 14, and discharges the cathode off gas to the cathode dischargepipe 42 of the cathode system device 16.

When supplying the cathode gas, based on operation of the air pump 54,the cathode system device 16 draws in air from the intake pipe 41, andguides the air to the air cleaner 70. As shown in FIGS. 2A and 2B,inside the air cleaner 70, the air flows into the internal space 72 a(the lower space 76 a) from the air introduction port 73 on the lowerside of the casing 72. The air, after having flowed to the rear sidethrough the lower space 76 a, rises upward and flows to the dust side 78a 1 of the upper space 78 a, and then passes through the air filter 80from the dust side 78 a 1 (see FIG. 3B). When the air passes through theair filter 80, foreign matter such as dust, dirt, water or the like areremoved, and the air moves to the clean side 78 a 2 (see FIG. 3B) of theupper space 78 a. The air that has flowed to the clean side 78 a 2 flowsout to the air lead-out port 74 on the upper side of the casing 72, andflows to the air pump 54 from the relay pipe 66 a that is connected tothe casing 72.

The air that has flowed to the air pump 54 is pressurized underoperation of the air pump 54, flows through the cathode supply pipe 40,passes through the intercooler 56 (the air-cooled type intercooler 56 aand the water-cooled type intercooler 56 b), and is adjusted to anappropriate temperature. In addition, when the air flows from theintercooler 56 to the humidifier 58, the air is humidified by thehumidifier 58, and the humidified air is supplied to the fuel cell stack12.

Next, a description will be given concerning actions of the air cleaner70 when the vehicle 11 receives a load from the side due to a collisionor the like. As shown in FIG. 4A, the air cleaner 70 receives the load,which is directed toward the side of the arrow A1, from the side of thevehicle 11 which is on the side of the arrow A2. Further, the peripheralstructures 92 are arranged in the surrounding vicinity on the side ofthe arrow A1 of the air cleaner 70, and when the casing 72 is broughtinto contact with the peripheral structures 92 upon receiving the loadthat is directed toward the side of the arrow A1, a load (reactionforce) directed toward the side of the arrow A2 is applied to the casing72. As examples of the peripheral structures 92, there may be citedother devices of the fuel cell system 10 (an oxygen-containing gassupply and discharge device, and a fuel gas supply and dischargedevice), or alternatively, a motor, a radiator, a headlight, and thelike provided in the vehicle 11. In addition, when such loads (in thedirection of the arrow A) are applied, the air filter 80, which isinclined with respect to the horizontal direction, rotates inside theinternal space 72 a without being pushed out with respect to the casing72 (the inclined posture thereof becomes oriented more toward thedirection of gravity).

In this instance, in an air cleaner 100 according to a comparative(conventional) example shown in FIG. 4B, an air filter 104 that isprovided inside a casing 102 is arranged so as to extend in a horizontaldirection. When the air filter 104 which is arranged in this mannerreceives a load from the side (in the direction of the arrow A), theload is applied to the entirety of the air filter 104. For this reason,the air filter 104 is less likely to be collapsed by a high bucklingload (in other words, the air filter 104 acts so as to be pushed outwith respect to the casing 72), and collapsing of the casing 72 issuppressed. As a result, the entirety of the air cleaner 100 movesaccompanying the load, and there is a concern that damage may occur tothe peripheral structures 92 around the periphery of the air cleaner 70.

In contrast thereto, the air filter 80 of the air cleaner 70 accordingto the present embodiment is inclined with respect to the horizontaldirection, whereby the height on the one side 80 a and the height on theother side 80 b of the air filter 80 are arranged differently (see FIG.4A). More specifically, the one side 80 a that is positioned on theupper side is on the side of the arrow A2, and the other side 80 b thatis positioned on the lower side is on the side of the arrow A1. Further,the air filter 80 is attached in a more inclined manner, without beingattached in a direction perpendicular with respect to the direction inwhich the side walls 79 a and 79 b of the casing 72 extend.

Therefore, when a load is received in the direction of the arrow A, theair filter 80 positively rotates in a counterclockwise direction (theone side 80 a moves toward the side of the arrow A1, and the other side80 b moves toward the side of the arrow A2). Accordingly, when the loadis received, almost no influence is imparted due to the rigidity of theair filter 80, and the side walls 79 a and 79 b move so as to approachone another and the casing 72 easily collapses. Stated otherwise, bypromoting collapsing of the casing 72, the inclined air filter 80 iscapable of suppressing movement of the air cleaner 70 as a whole, and inaccordance therewith, it is possible to reduce damage to the peripheralstructures 92 caused by the air cleaner 70.

Moreover, the present invention is not limited to the embodimentdescribed above, and various modifications may be made thereto in linewith the essence and gist of the present invention. For example, theinclined posture of the air filter 80 may be opposite to that shown inFIG. 3B. More specifically, the air filter 80 may have an inclinedposture in which the other side 80 b on the side of the arrow A1 ispositioned on an upper side, and the one side 80 a on the side of thearrow A2 is positioned on a lower side. Further, the shape of the casing72 may be formed in a manner in which the side walls 79 a and 79 b shownin FIG. 3B are inclined in an opposite orientation, or alternatively,may be formed with a non-inclined configuration (a rectangular shape, acubic shape, or the like).

Further, for example, as in the modification shown in FIG. 5A, the fuelcell system 10 may have a configuration in which an air cleaner 70A isarranged on a front side (the side of the arrow B1) in a horizontaldirection of the fuel cell stack 12. As viewed in cross section from theside (as shown in FIG. 5B), the air filter 80, which is inclined withrespect to the horizontal direction, may be provided in the interior ofthe casing 72 of the air cleaner 70A. More specifically, the air filter80 is inclined in a manner so that one side 80 a thereof on the side ofthe arrow B2 is positioned on an upper side, and the other side 80 b ofthe air filter 80 on the side of the arrow B1 is positioned on a lowerside.

The air cleaner 70A, which is arranged in the foregoing manner, allowsthe air filter 80 to be positively rotated when a load due to acollision or the like is applied in the front-rear direction (thedirection of the arrow B), whereby it is possible to promote collapsingof the casing 72. Accordingly, the air cleaner 70A can suppress damagefrom occurring to the fuel cell stack 12. Moreover, the inclined postureof the air filter 80 of the air cleaner 70A may be in an oppositedirection to that shown in FIG. 5B, and more specifically, may be in aninclined posture in which the one side 80 a on the side of the arrow B2is positioned on a lower side, and the other side 80 b on the side ofthe arrow B1 is positioned on an upper side.

A description will be given below concerning the technical concepts andeffects that can be grasped from the above-described embodiment.

One aspect of the present invention is characterized by the air cleaner70 or 70A provided in the cathode system device 16 of the fuel cellsystem 10 configured to be mounted in the fuel cell vehicle 11,including the casing 72 having the internal space 72 a through which theair flows, and the air filter 80 accommodated in the internal space 72a, wherein the air filter 80 has a flat plate shape, and is arranged onan outer side of the fuel cell stack 12 in a horizontal direction, andin a state of being inclined with respect to the horizontal direction.

The above-described air cleaner 70 or 70A is capable of easily promotingcollapsing of the casing 72 when a load is received. More specifically,the air filter 80, which is arranged in a state of being inclined withrespect to the horizontal direction, positively rotates without beingpushed out inside the casing 72 when such a load is received.Accordingly, the casing 72 is smoothly collapsed by the load, movementof the air cleaner 70 or 70A itself is suppressed, and damage caused toperipheral structures 92 around the periphery of the casing 72 can besignificantly reduced.

Further, the casing 72 includes the air introduction port 73 disposeddownwardly of the air filter 80, and the air lead-out port 74 disposedupwardly of the air filter 80, and the air flows from the airintroduction port 73, through the air filter 80, and to the air lead-outport 74. In accordance with such features, the air cleaner 70 or 70A iscapable of removing foreign matter from the air that is taken in, andsuch foreign matter (water or the like) can drop to the lower side ofthe casing 72.

Further, the air filter 80 has the three-layer structure 81.Consequently, foreign matter contained in the air that flows toward thefuel cell stack 12 can be more forcefully removed. In addition, in theair cleaner 70 or 70A, even if the air filter 80 is constructed rigidlyby the three-layer structure 81, since the air filter 80 is arranged inan inclined manner, it can be positively rotated, whereby it is possibleto promote collapsing of the casing 72.

Further, the air filter 80 includes the frame 88 disposed on the outerperiphery of the air filter 80, and which is fixed to the casing 72. Inaccordance with this feature, the air filter 80 can be stably fixed tothe casing 72 at an inclined posture. In addition, in the air cleaner 70or 70A, even if the frame 88 is disposed on the outer periphery of theair filter 80, since the air filter 80 is arranged in an inclinedmanner, it can be positively rotated, whereby it is possible to promotecollapsing of the casing 72.

Further, the air filter 80 includes the elastic member (the packing 90)that is adhered in an airtight manner to the side walls 79 a to 79 d ofthe casing 72. In accordance with this feature, the air is preventedfrom escaping from the outer periphery of the air filter 80. Further,the elastic member can be easily deformed, whereby the air filter 80 canbe suitably fixed while remaining at an inclined posture.

Further, the air filter 80 is installed in an inclined manner withrespect to the side wall (the side walls 79 a to 79 d) of the casing 72.In accordance with this feature, the air filter 80 can be furtherinclined with respect to the horizontal direction, and it is possible topromote collapsing of the casing 72 when a load is received.

Further, the air cleaner 70 is installed on the outer side of the fuelcell stack 12 in the vehicle widthwise direction, and the air filter 80is inclined with respect to the vehicle widthwise direction. Inaccordance with such features, the air cleaner 70 allows the air filter80 to be rotated inside the casing 72 when a load is applied theretofrom a side of the vehicle 11, whereby it is possible to promotecollapsing of the casing 72.

Further, the air cleaner 70 is installed on the front side of the fuelcell stack 12, and the air filter 80 is inclined with respect to afront-rear direction. In accordance with such features, the air cleaner70 allows the air filter 80 to be rotated inside the casing 72 when aload is applied thereto from the front of the vehicle 11, whereby it ispossible to promote collapsing of the casing 72.

What is claimed is:
 1. An air cleaner provided in a cathode systemdevice of a fuel cell system configured to be mounted in a fuel cellvehicle, the air cleaner comprising: a casing having an internal spacethrough which air flows; and an air filter accommodated in the internalspace; wherein the air filter has a flat plate shape, and is arranged onan outer side of a fuel cell stack in a horizontal direction, and in astate of being inclined with respect to the horizontal direction.
 2. Theair cleaner according to claim 1, wherein: the casing comprises an airintroduction port disposed downwardly of the air filter, and an airlead-out port disposed upwardly of the air filter; and the air flowsfrom the air introduction port, through the air filter, and to the airlead-out port.
 3. The air cleaner according to claim 1, wherein the airfilter has a three-layer structure.
 4. The air cleaner according toclaim 1, wherein the air filter includes a frame disposed on an outerperiphery of the air filter, and which is fixed to the casing.
 5. Theair cleaner according to claim 4, wherein the air filter includes anelastic member that is adhered in an airtight manner to side walls ofthe casing.
 6. The air cleaner according to claim 1, wherein the airfilter is installed in an inclined manner with respect to a side wall ofthe casing.
 7. The air cleaner according to claim 1, wherein: the aircleaner is installed on an outer side of the fuel cell stack in avehicle widthwise direction; and the air filter is inclined with respectto the vehicle widthwise direction.
 8. The air cleaner according toclaim 1, wherein: the air cleaner is installed on a front side of thefuel cell stack; and the air filter is inclined with respect to afront-rear direction.